You advocate strongly for FX. That's fine. Most of us on this forum have made the move to FX for a variety of our own reasons. I am sure Nikon is very pleased.

However, given the personal situation of the op as a hobbyist photographer and student, I think you owe it to him to explain how your recommendation is going to improve his photography in a meaningful way for his particular needs.

ultimitsu wrote:

AustinTed wrote:

ultimitsu wrote:

I hold the complete opposite view. To get the same IQ, lenses cost a lot less with FF than APS-C.

it has been my own experience that I've spent more on glass after moving to FX.

Of course, that is the experience of most people. it is so merely because as a hobby people gradually spend more money into photography. Upgrading from aps-c to FF is just one of these steps. it is neither the beginning nor the end of the ever increasing spending.

If he wants the same IQ he can stay where he is.

That is not the point. I was responding to the suggestion that "anybody with budget sensitivities steer clear and work on glass first". My point is, those that are budget sensitive, but can afford FF, should go FF because it is cheaper than pursuing good IQ while staying with APs-C.

In regards to OP. if he can sell 17-55 and D300 for a good price he may well get a free ride with D600 + 24-85, from there on every other lens he uses will give him significantly better IQ than he would otherwise get with D300.

Since the op has decent glass he can improve IQ by moving to a more recent dx body as an alternative to jumping to FX and replacing both body and glass.

And it is my view that that is an ultimately more expensive option - staying with APs-C and buy expensive glass.

But my suggestion is that he just enjoy what he has.

You suggestion was "work on glass first", buying more expensive glass is definitely not "enjoy what he has".